With development of electronic technologies, a frequency characteristic of an electronic element in a silicon integrated circuit, for example, a power gain limit frequency, gradually approaches a physical law limit. Therefore, how to further improve the frequency characteristic of the electronic element becomes an important technical concern in the art.
A field effect transistor is a common electronic element. In the prior art, a field effect transistor is usually prepared by using a silicon-based semiconductor material. To provide a better frequency characteristic, a two-dimensional material, for example, graphene, may be used instead of the silicon-based semiconductor material, thereby preparing a graphene-material-based field effect transistor. The graphene material has advantages of a two-dimensional characteristic, a high electron mobility rate, and a high saturation velocity. Therefore, the graphene-material-based field effect transistor can have a better frequency characteristic, for example, a higher cut-off frequency, than the conventional silicon-based field effect transistor.
However, because the graphene-material-based field effect transistor still uses a conventional insulation gate field effect transistor structure, problems such as a low output current, a great carrier scattering effect, and an obvious parasitic effect, tend to result. Consequently, the graphene-material-based field effect transistor does not have an ideal frequency characteristic.